This invention relates to an x-ray imaging system which includes a device for filtering x-rays, and, more particularly, to a system employing a spectral filter for filtering x-rays emanating from the exit port of an x-ray tube used in imaging systems.
The filtering of x-rays, or x-ray filtration, is a step that has been employed in x-ray systems, for example, in medical imaging systems, in an effort to improve the images obtained. Materials employed in constructing x-ray spectral filters have included aluminum and copper, and, for low energy applications such as mammography, filters made of rhodium and molybdenum have been used. The material used and the thickness of the filter influence the ability of a filter to absorb x-rays. The spectral filtering by such x-ray filters is performed in order to improve the quality of the image obtained. The filtering of the x-rays to improve image quality has heretofore focused substantially exclusively on blocking low energy x-rays from reaching the patient, and/or from reaching the detector.
The principal goal in using x-ray spectral filtering is to aid in improving the image obtained by the imager, without adversely affecting the object undergoing imaging. Various aspects of an overall imaging system can affect the image quality. The problem to be solved by the present invention is to improve, through the use of spectral filtering of the x-ray tube, the quality of an image obtained in an imaging process, while reducing the dosage or exposure of x-rays to the patient.
An x-ray imaging system is provided having an x-ray source, an x-ray detector, and at least one spectral radiation filter, the spectral radiation filter being disposed between the source and the object to be imaged.